Background: Smokers have a substantially increased risk of intra- and postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence. The preoperative period may be a well chosen time to offer smoking cessation interventions due to increased patient motivation.
Objectives: The objective of this review was to assess the effect of preoperative smoking intervention on smoking cessation in the postoperative period and longer term. We also set out to determine the effect of smoking cessation on the incidence of postoperative complications.
Search strategy: The specialized register of the Cochrane Tobacco Addiction Group was searched using the free text and keywords (surgery) OR (operation) OR (anaesthesia) or (anesthesia). MEDLINE, EMBASE and CINAHL were also searched, combining tobacco- and surgery-related terms. Most recent search February 2005.
Selection criteria: We considered randomized trials which recruited smokers prior to surgery, offered a smoking cessation intervention, and measured abstinence from smoking in the preoperative and postoperative periods. We also considered randomized trials of the effect of smoking cessation on the incidence of intra- and postoperative complications.
Data collection and analysis: The authors independently assessed studies to determine eligibility. The results were discussed between the authors.
Main results: Four trials met the inclusion criteria. All trials significantly reduced preoperative smoking but the effect sizes were heterogeneous so a pooled effect was not estimated. Only two trials reported the effect of the smoking intervention on wound complications, and the results were heterogeneous, with a significant reduction in wound-related complications, cardiopulmonary complications and the overall risk of any complication in one trial, and no evidence of a difference in complications in the other. The effect on longer term smoking cessation was not significant in either of the two trials with follow up beyond the perioperative period.
Authors' conclusions: Preoperative smoking interventions are effective for changing smoking behaviour perioperatively. Direct evidence that reducing or stopping smoking reduces the risk of complications is based on two small trials with differing results. The impact on complications may depend on how long before surgery the smoking behaviour is changed, whether smoking is reduced or stopped completely, and the type of surgery.